A raster band.
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Inheritance diagram for Geo::GDAL::Band:

Collaboration diagram for Geo::GDAL::Band:

Public Member Functions
public method	AdviseRead ()

public Geo::GDAL::RasterAttributeTable	AttributeTable (scalar AttributeTable)

public list	BlockSize ()

public list	CategoryNames (array names)

public scalar	Checksum (scalar xoff=0, scalar yoff=0, scalar xsize=undef, scalar ysize=undef)

public hashref	ClassCounts (scalar classifier, scalar progress=undef, scalar progress_data=undef)

public scalar	ColorInterpretation (scalar color_interpretation)

public method	ColorInterpretations ()

public Geo::GDAL::ColorTable	ColorTable (scalar ColorTable)

public method	ComputeBandStats (scalar samplestep=1)

public method	ComputeRasterMinMax (scalar approx_ok=0)

public list	ComputeStatistics (scalar approx_ok, scalar progress=undef, scalar progress_data=undef)

public Geo::OGR::Layer	Contours (scalar DataSource, hashref LayerConstructor, scalar ContourInterval, scalar ContourBase, arrayref FixedLevels, scalar NoDataValue, scalar IDField, scalar ElevField, coderef Progress, scalar ProgressData)

public method	CreateMaskBand (array flags)

public scalar	DataType ()

public Geo::GDAL::Dataset	Dataset ()

public scalar	DeleteNoDataValue ()

public Geo::GDAL::Band	Distance (hash params)

public method	Domains ()

public method	Fill (scalar real_part, scalar imag_part=0.0)

public method	FillNoData (scalar mask, scalar max_search_dist, scalar smoothing_iterations, scalar options, coderef progress, scalar progress_data)

public method	FlushCache ()

public scalar	GetBandNumber ()

public method	GetBlockSize ()

public list	GetDefaultHistogram (scalar force=1, coderef progress=undef, scalar progress_data=undef)

public list	GetHistogram (hash parameters)

public Geo::GDAL::Band	GetMaskBand ()

public list	GetMaskFlags ()

public scalar	GetMaximum ()

public scalar	GetMinimum ()

public Geo::GDAL::Band	GetOverview (scalar index)

public scalar	GetOverviewCount ()

public list	GetStatistics (scalar approx_ok, scalar force)

public method	HasArbitraryOverviews ()

public list	MaskFlags ()

public scalar	NoDataValue (scalar NoDataValue)

public scalar	PackCharacter ()

public method	Piddle (scalar piddle, scalar xoff=0, scalar yoff=0, scalar xsize=< width >, scalar ysize=< height >, scalar xdim, scalar ydim)

public Geo::OGR::Layer	Polygonize (hash params)

public method	RasterAttributeTable ()

public scalar	ReadRaster (hash params)

public array reference	ReadTile (scalar xoff=0, scalar yoff=0, scalar xsize=< width >, scalar ysize=< height >)

public method	Reclassify (scalar classifier, scalar progress=undef, scalar progress_data=undef)

public method	RegenerateOverview (Geo::GDAL::Band overview, scalar resampling, coderef progress, scalar progress_data)

public method	RegenerateOverviews (arrayref overviews, scalar resampling, coderef progress, scalar progress_data)

public method	ScaleAndOffset (scalar scale, scalar offset)

public list	SetDefaultHistogram (scalar min, scalar max, scalar histogram)

public method	SetStatistics (scalar min, scalar max, scalar mean, scalar stddev)

public Geo::GDAL::Band	Sieve (hash params)

public list	Size ()

public method	Unit (scalar type)

public method	WriteRaster (hash params)

public method	WriteTile (scalar data, scalar xoff=0, scalar yoff=0)

Public Member Functions inherited from Geo::GDAL::MajorObject
public scalar	Description (scalar description)

public method	Domains ()

public scalar	GetDescription ()

public hash reference	GetMetadata (scalar domain="")

public method	GetMetadataDomainList ()

public hash reference	Metadata (hashref metadata=undef, scalar domain= '')

public method	SetDescription (scalar NewDesc)

public method	SetMetadata (hashref metadata, scalar domain="")

Public Member Functions inherited from Geo::GDAL
public method	ApplyVerticalShiftGrid ()

public method	BuildVRT ()

public method	CPLBinaryToHex ()

public method	CPLHexToBinary ()

public method	CreatePansharpenedVRT ()

public scalar	DataTypeIsComplex (scalar DataType)

public list	DataTypeValueRange (scalar DataType)

public list	DataTypes ()

public scalar	DecToDMS (scalar angle, scalar axis, scalar precision=2)

public scalar	DecToPackedDMS (scalar dec)

public method	DontUseExceptions ()

public Geo::GDAL::Driver	Driver (scalar Name)

public list	DriverNames ()

public list	Drivers ()

public method	EscapeString ()

public scalar	FindFile (scalar basename)

public method	FinderClean ()

public method	GOA2GetAccessToken ()

public method	GOA2GetAuthorizationURL ()

public method	GOA2GetRefreshToken ()

public method	GetActualURL ()

public scalar	GetCacheMax ()

public scalar	GetCacheUsed ()

public scalar	GetConfigOption (scalar key)

public scalar	GetDataTypeSize (scalar DataType)

public method	GetErrorCounter ()

public method	GetFileSystemOptions ()

public method	GetFileSystemsPrefixes ()

public method	GetJPEG2000StructureAsString ()

public method	GetSignedURL ()

public Geo::GDAL::Driver	IdentifyDriver (scalar path, scalar siblings)

public method	IdentifyDriverEx ()

public method	MkdirRecursive ()

public Geo::GDAL::Dataset	Open (hash params)

public Geo::GDAL::Dataset	OpenEx (hash params)

public list	OpenFlags ()

public scalar	PackCharacter (scalar DataType)

public scalar	PackedDMSToDec (scalar packed)

public method	PopFinderLocation ()

public method	PushFinderLocation (scalar path)

public list	RIOResamplingTypes ()

public list	ResamplingTypes ()

public method	RmdirRecursive ()

public method	SetCacheMax (scalar Bytes)

public method	SetConfigOption (scalar key, scalar value)

public method	UseExceptions ()

public method	VSICurlClearCache ()

public method	VSIFEofL ()

public method	VSIFOpenExL ()

public method	VSIGetLastErrorMsg ()

public method	VSIGetLastErrorNo ()

public scalar	VersionInfo (scalar request= 'VERSION_NUM')

public scalar	errstr ()

Public Attributes
scalar	XSize
	Object attribute. scalar (access as $band->{XSize})

scalar	YSize
	Object attribute. scalar (access as $band->{YSize})

Detailed Description

A raster band.

Definition at line 1379 of file all.dox.

Member Function Documentation

public method Geo::GDAL::Band::AdviseRead ( )

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public Geo::GDAL::RasterAttributeTable Geo::GDAL::Band::AttributeTable ( scalar AttributeTable )

Object method.

Parameters

AttributeTable [optional] A Geo::GDAL::RasterAttributeTable object.

Returns: a new Geo::GDAL::RasterAttributeTable object, whose data is
contained within the band.

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public list Geo::GDAL::Band::BlockSize ( )

Object method.
A.k.a GetBlockSize

Returns: The size of a preferred i/o raster block size as a list
(width, height).

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public list Geo::GDAL::Band::CategoryNames ( array names )

Object method.

Parameters

names [optional]

Returns

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public scalar Geo::GDAL::Band::Checksum	(	scalar	xoff = `0`,
		scalar	yoff = `0`,
		scalar	xsize = `undef`,
		scalar	ysize = `undef`
	)

Object method.
Computes a checksum from the raster or a part of it.

Parameters

xoff
yoff
xsize
ysize

Returns: the checksum.

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public hashref Geo::GDAL::Band::ClassCounts	(	scalar	classifier,
		scalar	progress = `undef`,
		scalar	progress_data = `undef`
	)

Object method.
Compute the counts of cell values or number of cell values in ranges.

Note: Classifier is required only for float bands.; NoData values are counted similar to other values when
classifier is not defined for integer rasters.

Parameters

classifier

Anonymous array of format [ $comparison,
$classifier ], where $comparison is a string '<', '<=', '>', or '>='
and $classifier is an anonymous array of format [ $value,
$value|$classifier, $value|$classifier ], where $value is a numeric
value against which the reclassified value is compared to. If the
comparison returns true, then the second $value or $classifier is
applied, and if not then the third $value or $classifier.

In the example below, the line is divided into ranges
[-inf..3), [3..5), and [5..inf], i.e., three ranges with class
indexes 0, 1, and 2. Note that the indexes are used as keys for
class counts and not the class values (here 1.0, 2.0, and 3.0),
which are used in Geo::GDAL::Band::Reclassify.

<br>$classifier = [ '<', [5.0, [3.0, 1.0, 2.0], 3.0] ];
<br># Howto create this $classifier from @class_boundaries:
<br>my $classifier = ['<='];
<br>my $tree = [$class_boundaries[0], 0, 1];
<br>for my $i (1 .. $#class_boundaries) {
<br>    $tree = [$class_boundaries[$i], [@$tree], $i+1];
<br>}
<br>push @$classifier, $tree;
<br>

Returns: a reference to an anonymous hash, which contains the class
values (indexes) as keys and the number of cells with that value or
in that range as values. If the subroutine is user terminated an
error is raised.

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public scalar Geo::GDAL::Band::ColorInterpretation ( scalar color_interpretation )

Object method.

Note: a.k.a. GetRasterColorInterpretation and GetColorInterpretation
(get only and returns an integer), SetRasterColorInterpretation and
SetColorInterpretation (set only and requires an integer)

Parameters

color_interpretation [optional] new color interpretation, one
of Geo::GDAL::Band::ColorInterpretations.

Returns: The color interpretation of this band. One of Geo::GDAL::Band::ColorInterpretations.

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public method Geo::GDAL::Band::ColorInterpretations ( )

Package subroutine.

Returns: a list of types of color interpretation for raster
bands. These are currently:
AlphaBand, BlackBand, BlueBand, CyanBand, GrayIndex, GreenBand, HueBand, LightnessBand, MagentaBand, PaletteIndex, RedBand, SaturationBand, Undefined, YCbCr_CbBand, YCbCr_CrBand, YCbCr_YBand, and YellowBand.

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public Geo::GDAL::ColorTable Geo::GDAL::Band::ColorTable ( scalar ColorTable )

Object method.
Get or set the color table of this band.

Parameters

ColorTable [optional] a Geo::GDAL::ColorTable object

Returns: A new Geo::GDAL::ColorTable object which represents the
internal color table associated with this band. Returns undef this
band does not have an associated color table.

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public method Geo::GDAL::Band::ComputeBandStats ( scalar samplestep = 1 )

Object method.

Parameters

samplestep the row increment in computing the statistics.

Note: Returns uncorrected sample standard deviation.

See also Geo::GDAL::Band::ComputeStatistics.

Returns: a list (mean, stddev).

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public method Geo::GDAL::Band::ComputeRasterMinMax ( scalar approx_ok = 0 )

Object method.

Returns: arrayref MinMax = [min, max]

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public list Geo::GDAL::Band::ComputeStatistics	(	scalar	approx_ok,
		scalar	progress = `undef`,
		scalar	progress_data = `undef`
	)

Object method.

Parameters

approx_ok Whether it is allowed to compute the statistics
based on overviews or similar.

Note: Returns uncorrected sample standard deviation.

See also Geo::GDAL::Band::ComputeBandStats.

Returns: a list ($min, $max, $mean, $stddev).

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public Geo::OGR::Layer Geo::GDAL::Band::Contours	(	scalar	DataSource,
		hashref	LayerConstructor,
		scalar	ContourInterval,
		scalar	ContourBase,
		arrayref	FixedLevels,
		scalar	NoDataValue,
		scalar	IDField,
		scalar	ElevField,
		coderef	Progress,
		scalar	ProgressData
	)

Object method.
Generate contours for this raster band. This method can also be used with named parameters.

Note: This method is a wrapper for ContourGenerate.

An example:

 use Geo::GDAL;
 $dem = Geo::GDAL::Open('dem.gtiff');
 $contours = $dem->Band->Contours(ContourInterval => 10, ElevField => 'z');
 $n = $contours->GetFeatureCount;

Parameters

DataSource	a Geo::OGR::DataSource object, default is a Memory data source
LayerConstructor	data for Geo::OGR::DataSource::CreateLayer, default is {Name => 'contours'}
ContourInterval	default is 100
ContourBase	default is 0
FixedLevels	a reference to a list of fixed contour levels, default is []
NoDataValue	default is undef
IDField	default is '', i.e., no field (the field is created if this is given)
ElevField	default is '', i.e., no field (the field is created if this is given)
progress	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, progress_data)
progress_data	[optional]

Returns

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public method Geo::GDAL::Band::CreateMaskBand ( array flags )

Object method.

Note: May invalidate any previous mask band obtained with Geo::GDAL::Band::GetMaskBand.

Parameters

flags one or more mask flags. The flags are Geo::GDAL::Band::MaskFlags.

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public Geo::GDAL::Dataset Geo::GDAL::Band::Dataset ( )

Object method.

Returns: The dataset which this band belongs to.

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public scalar Geo::GDAL::Band::DataType ( )

Object method.

Returns: The data type of this band. One of Geo::GDAL::DataTypes.

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public scalar Geo::GDAL::Band::DeleteNoDataValue ( )

Object method.

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public Geo::GDAL::Band Geo::GDAL::Band::Distance ( hash params )

Object method.
Compute distances to specific cells of this raster.

Parameters

params Named parameters:
- Distance A raster band, into which the distances are computed. If not given, a not given, a new in-memory raster band is created and returned. The data type of the raster can be given in the options.
- Options Hash of options. Options are:
- Values A list of cell values in this band to measure the distance from. If this option is not provided, the distance will be computed to non-zero pixel values. Currently pixel values are internally processed as integers.
- DistUnits=PIXEL|GEO Indicates whether distances will be computed in cells or in georeferenced units. The default is pixel units. This also determines the interpretation of MaxDist.
- MaxDist=n The maximum distance to search. Distances greater than this value will not be computed. Instead output cells will be set to a NoData value.
- NoData=n The NoData value to use on the distance band for cells that are beyond MaxDist. If not provided, the distance band will be queried for a NoData value. If one is not found, 65535 will be used (255 if the type is Byte).
- Use_Input_NoData=YES|NO If this option is set, the NoData value of this band will be respected. Leaving NoData cells in the input as NoData pixels in the distance raster.
- Fixed_Buf_Val=n If this option is set, all cells within the MaxDist threshold are set to this value instead of the distance value.
- DataType The data type for the result if it is not given.
- Progress Progress function.
- ProgressData Additional parameter for the progress function.

Note: This GDAL function behind this API is called GDALComputeProximity.

Returns: The distance raster.

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public method Geo::GDAL::Band::Domains ( )

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public method Geo::GDAL::Band::Fill	(	scalar	real_part,
		scalar	imag_part = `0.0`
	)

Object method.
Fill the band with a constant value.

Parameters

real_part	Real component of fill value.
imag_part	Imaginary component of fill value.

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public method Geo::GDAL::Band::FillNoData	(	scalar	mask,
		scalar	max_search_dist,
		scalar	smoothing_iterations,
		scalar	options,
		coderef	progress,
		scalar	progress_data
	)

Object method.
Interpolate values for cells in this raster. The cells to fill
should be marked in the mask band with zero.

Parameters

mask	[optional] a mask band indicating cells to be interpolated (zero valued) (default is to get it with Geo::GDAL::Band::GetMaskBand).
max_search_dist	[optional] the maximum number of cells to search in all directions to find values to interpolate from (default is 10).
smoothing_iterations	[optional] the number of 3x3 smoothing filter passes to run (0 or more) (default is 0).
options	[optional] A reference to a hash. No options have been defined so far for this algorithm (default is {}).
progress	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, progress_data) (default is undef).
progress_data	[optional] (default is undef). Documentation for GDAL algorithms

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public method Geo::GDAL::Band::FlushCache ( )

Object method.
Write cached data to disk. There is usually no need to call this
method.

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public scalar Geo::GDAL::Band::GetBandNumber ( )

Object method.

Returns: The index of this band in the parent dataset list of bands.

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public method Geo::GDAL::Band::GetBlockSize ( )

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public list Geo::GDAL::Band::GetDefaultHistogram	(	scalar	force = `1`,
		coderef	progress = `undef`,
		scalar	progress_data = `undef`
	)

Object method.

Parameters

force	true to force the computation
progress	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, progress_data)
progress_data	[optional]

Note: See Note in Geo::GDAL::Band::GetHistogram.

Returns: a list: ($min, $max, arrayref histogram).

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public list Geo::GDAL::Band::GetHistogram ( hash parameters )

Object method.
Compute histogram from the raster.

Parameters

parameters Named parameters:
- Min the lower bound, default is -0.5
- Max the upper bound, default is 255.5
- Buckets the number of buckets in the histogram, default is 256
- IncludeOutOfRange whether to use the first and last values in the returned list
for out of range values, default is false;
the bucket size is (Max-Min) / Buckets if this is false and
(Max-Min) / (Buckets-2) if this is true
- ApproxOK if histogram can be computed from overviews, default is false
- Progress an optional progress function, the default is undef
- ProgressData data for the progress function, the default is undef

Note: Histogram counts are treated as strings in the bindings to be
able to use large integers (if GUIntBig is larger than Perl IV). In
practice this is only important if you have a 32 bit machine and
very large bucket counts. In those cases it may also be necessary to
use Math::BigInt.

Returns: a list which contains the count of values in each bucket

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public Geo::GDAL::Band Geo::GDAL::Band::GetMaskBand ( )

Object method.

Returns: the mask band associated with this
band.

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public list Geo::GDAL::Band::GetMaskFlags ( )

Object method.

Returns: the mask flags of the mask band associated with this
band. The flags are one or more of Geo::GDAL::Band::MaskFlags.

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public scalar Geo::GDAL::Band::GetMaximum ( )

Object method.

Note: Call Geo::GDAL::Band::ComputeStatistics before calling
GetMaximum to make sure the value is computed.

Returns: statistical minimum of the band or undef if statistics are
not kept or computed in scalar context. In list context returns the
maximum value or a (kind of) maximum value supported by the data
type and a boolean value, which indicates which is the case (true is
first, false is second).

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public scalar Geo::GDAL::Band::GetMinimum ( )

Object method.

Note: Call Geo::GDAL::Band::ComputeStatistics before calling
GetMinimum to make sure the value is computed.

Returns: statistical minimum of the band or undef if statistics are
not kept or computed in scalar context. In list context returns the
minimum value or a (kind of) minimum value supported by the data
type and a boolean value, which indicates which is the case (true is
first, false is second).

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public Geo::GDAL::Band Geo::GDAL::Band::GetOverview ( scalar index )

Object method.

Parameters

index 0..GetOverviewCount-1

Returns: a Geo::GDAL::Band object, which represents the internal
overview band, or undef. if the index is out of bounds.

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public scalar Geo::GDAL::Band::GetOverviewCount ( )

Object method.

Returns: the number of overviews available of the band.

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public list Geo::GDAL::Band::GetStatistics	(	scalar	approx_ok,
		scalar	force
	)

Object method.

Parameters

approx_ok	Whether it is allowed to compute the statistics based on overviews or similar.
force	Whether to force scanning of the whole raster.

Note: Uses Geo::GDAL::Band::ComputeStatistics internally.

Returns: a list ($min, $max, $mean, $stddev).

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public method Geo::GDAL::Band::HasArbitraryOverviews ( )

Object method.

Returns: true or false.

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public list Geo::GDAL::Band::MaskFlags ( )

Package subroutine.

Returns: the list of mask flags. These are
- AllValid: There are no invalid cell, all mask values will be 255.
When used this will normally be the only flag set.
- PerDataset: The mask band is shared between all bands on the dataset.
- Alpha: The mask band is actually an alpha band and may have values
other than 0 and 255.
- NoData: Indicates the mask is actually being generated from NoData values.
(mutually exclusive of Alpha).

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public scalar Geo::GDAL::Band::NoDataValue ( scalar NoDataValue )

Object method.
Get or set the "no data" value.

Parameters

NoDataValue [optional]

Note: $band->NoDataValue(undef) sets the NoData value to the
Posix floating point maximum. Use Geo::GDAL::Band::DeleteNoDataValue
to stop this band using a NoData value.

Returns: The NoData value or undef in scalar context. An undef
value indicates that there is no NoData value associated with this
band.

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public scalar Geo::GDAL::Band::PackCharacter ( )

Object method.

Returns: The character to use in Perl pack and unpack for the data of this band.

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public method Geo::GDAL::Band::Piddle	(	scalar	piddle,
		scalar	xoff = `0`,
		scalar	yoff = `0`,
		scalar	xsize = `<width>`,
		scalar	ysize = `<height>`,
		scalar	xdim,
		scalar	ydim
	)

Object method.
Read or write band data from/into a piddle.

Note: The PDL module must be available for this method to work. Also, you
should 'use PDL' in the code that you use this method.

Parameters

piddle	[only when writing] The piddle from which to read the data to be written into the band.
xoff,yoff	The offset for data in the band, default is top left (0, 0).
xsize,ysize	[optional] The size of the window in the band.
xdim,ydim	[optional, only when reading from a band] The size of the piddle to create.

Returns: A new piddle when reading from a band (no not use when writing into a band).

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# Number of lines of code in Piddle: 50
sub Piddle {
    # TODO: add Piddle sub to dataset too to make Width x Height x Bands piddles
    error("PDL is not available.") unless $Geo::GDAL::HAVE_PDL;
    my $self = shift;
    my $t = $self->{DataType};
    unless (defined wantarray) {
        my $pdl = shift;
        error("The datatype of the Piddle and the band do not match.")
          unless $PDL2DATATYPE{$pdl->get_datatype} == $t;
        my ($xoff, $yoff, $xsize, $ysize) = @_;
        $xoff //= 0;
        $yoff //= 0;
        my $data = $pdl->get_dataref();
        my ($xdim, $ydim) = $pdl->dims();
        if ($xdim > $self->{XSize} - $xoff) {
            warn "Piddle XSize too large ($xdim) for this raster band (width = $self->{XSize}, offset = $xoff).";
            $xdim = $self->{XSize} - $xoff;
        }
        if ($ydim > $self->{YSize} - $yoff) {
            $ydim = $self->{YSize} - $yoff;
            warn "Piddle YSize too large ($ydim) for this raster band (height = $self->{YSize}, offset = $yoff).";
        }
        $xsize //= $xdim;
        $ysize //= $ydim;
        $self->_WriteRaster($xoff, $yoff, $xsize, $ysize, $data, $xdim, $ydim, $t, 0, 0);
        return;
    }
    my ($xoff, $yoff, $xsize, $ysize, $xdim, $ydim, $alg) = @_;
    $xoff //= 0;
    $yoff //= 0;
    $xsize //= $self->{XSize} - $xoff;
    $ysize //= $self->{YSize} - $yoff;
    $xdim //= $xsize;
    $ydim //= $ysize;
    $alg //= 'NearestNeighbour';
    $alg = s2i(rio_resampling => $alg);
    my $buf = $self->_ReadRaster($xoff, $yoff, $xsize, $ysize, $xdim, $ydim, $t, 0, 0, $alg);
    my $pdl = PDL->new;
    my $datatype = $DATATYPE2PDL{$t};
    error("The band datatype is not supported by PDL.") if $datatype < 0;
    $pdl->set_datatype($datatype);
    $pdl->setdims([$xdim, $ydim]);
    my $data = $pdl->get_dataref();
    $$data = $buf;
    $pdl->upd_data;
    # FIXME: we want approximate equality since no data value can be very large floating point value
    my $bad = GetNoDataValue($self);
    return $pdl->setbadif($pdl == $bad) if defined $bad;
    return $pdl;
}

public Geo::OGR::Layer Geo::GDAL::Band::Polygonize ( hash params )

Object method.
Polygonize this raster band.

Parameters

params Named parameters:
- Mask A raster band, which is used as a mask to select polygonized areas. Default is undef.
- OutLayer A vector layer into which the polygons are written. If not given, an in-memory layer 'polygonized' is created and returned.
- PixValField The name of the field in the output layer into which the cell value of the polygon area is stored. Default is 'val'.
- Options Hash or list of options. Connectedness can be set to 8
to use 8-connectedness, otherwise 4-connectedness is
used. ForceIntPixel can be set to 1 to force using a 32 bit int buffer
for cell values in the process. If this is not set and the data type
of this raster does not fit into a 32 bit int buffer, a 32 bit float
buffer is used.
- Progress Progress function.
- ProgressData Additional parameter for the progress function.

Returns: Output vector layer.

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public method Geo::GDAL::Band::RasterAttributeTable ( )

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public scalar Geo::GDAL::Band::ReadRaster ( hash params )

Object method.
Read data from the band.

Parameters

params Named parameters:
- XOff x offset (cell coordinates) (default is 0)
- YOff y offset (cell coordinates) (default is 0)
- XSize width of the area to read (default is the width of the band)
- YSize height of the area to read (default is the height of the band)
- BufXSize (default is undef, i.e., the same as XSize)
- BufYSize (default is undef, i.e., the same as YSize)
- BufType data type of the buffer (default is the data type of the band)
- BufPixelSpace (default is 0)
- BufLineSpace (default is 0)
- ResampleAlg one of Geo::GDAL::RIOResamplingTypes (default is 'NearestNeighbour'),
- Progress reference to a progress function (default is undef)
- ProgressData (default is undef)

Entry in GDAL docs (method RasterIO)

Returns: a buffer, open the buffer with unpack function of Perl. See Geo::GDAL::Band::PackCharacter.

Code:

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public array reference Geo::GDAL::Band::ReadTile	(	scalar	xoff = `0`,
		scalar	yoff = `0`,
		scalar	xsize = `<width>`,
		scalar	ysize = `<height>`
	)

Object method.
Read band data into a Perl array.

Note: Accessing band data in this way is slow. Consider using PDL and Geo::GDAL::Band::Piddle.

Usage example (print the data from a band):

 print "@$_\n" for ( @{ $band->ReadTile() } );
 

Another usage example (process the data of a large dataset that has one band):

 my($W,$H) = $dataset->Band()->Size();
 my($xoff,$yoff,$w,$h) = (0,0,200,200);
 while (1) {
 if ($xoff >= $W) {
 $xoff = 0;
 $yoff += $h;
 last if $yoff >= $H;
 }
 my $data = $dataset->Band(1)->ReadTile($xoff,$yoff,min($W-$xoff,$w),min($H-$yoff,$h));
 # add your data processing code here
 $dataset->Band(1)->WriteTile($data,$xoff,$yoff);
 $xoff += $w;
 }
 
 sub min {
 return $_[0] < $_[1] ? $_[0] : $_[1];
 }

Parameters

xoff	Number of cell to skip before starting to read from a row. Pixels are read from left to right.
yoff	Number of cells to skip before starting to read from a column. Pixels are read from top to bottom.
xsize	Number of cells to read from each row.
ysize	Number of cells to read from each column.

Returns: a two-dimensional Perl array, organizes as data->[y][x], y =
0..height-1, x = 0..width-1. I.e., y is row and x is column.

Code:

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public method Geo::GDAL::Band::Reclassify	(	scalar	classifier,
		scalar	progress = `undef`,
		scalar	progress_data = `undef`
	)

Object method.
Reclassify the cells in the band.

Note: NoData values in integer rasters are reclassified if
explicitly specified in the hash classifier. However, they are not
reclassified to the default value, if one is specified. In real
valued rasters nodata cells are not reclassified.; If the subroutine is user terminated or the classifier is
incorrect, already reclassified cells will stay reclassified but an
error is raised.

Parameters

classifier For integer rasters an anonymous hash, which
contains old class values as keys and new class values as values, or
an array classifier as in Geo::GDAL::Band::ClassCounts. In a hash
classifier a special key '*' (star) can be used as default, to act
as a fallback new class value. For real valued rasters the
classifier is as in Geo::GDAL::Band::ClassCounts.

Code:

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public method Geo::GDAL::Band::RegenerateOverview	(	Geo::GDAL::Band	overview,
		scalar	resampling,
		coderef	progress,
		scalar	progress_data
	)

Object method.

Parameters

overview	a Geo::GDAL::Band object for the overview.
resampling	[optional] the resampling method (one of Geo::GDAL::RIOResamplingTypes) (default is Average).
progress	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, progress_data)
progress_data	[optional]

Code:

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public method Geo::GDAL::Band::RegenerateOverviews	(	arrayref	overviews,
		scalar	resampling,
		coderef	progress,
		scalar	progress_data
	)

Object method.

Todo:: This is not yet available

Parameters

overviews	a list of Geo::GDAL::Band objects for the overviews.
resampling	[optional] the resampling method (one of Geo::GDAL::RIOResamplingTypes) (default is Average).
progress	[optional] a reference to a subroutine, which will be called with parameters (number progress, string msg, progress_data)
progress_data	[optional]

Code:

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public method Geo::GDAL::Band::ScaleAndOffset	(	scalar	scale,
		scalar	offset
	)

Object method.
Scale and offset are used to transform raw cell values into the
units returned by GetUnits(). The conversion function is:

Units value = (raw value * scale) + offset

Returns: a list ($scale, $offset), the values are undefined if they
are not set.

Since: version 1.9 of the bindings.

Code:

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public list Geo::GDAL::Band::SetDefaultHistogram	(	scalar	min,
		scalar	max,
		scalar	histogram
	)

Object method.

Parameters

min
max

Note: See Note in Geo::GDAL::Band::GetHistogram.

Parameters

histogram reference to an array containing the histogram

Code:

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public method Geo::GDAL::Band::SetStatistics	(	scalar	min,
		scalar	max,
		scalar	mean,
		scalar	stddev
	)

Object method.
Save the statistics of the band if possible (the format can save
arbitrary metadata).

Parameters

min
max
mean
stddev

Code:

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public Geo::GDAL::Band Geo::GDAL::Band::Sieve ( hash params )

Object method.
Remove small areas by merging them into the largest neighbour area.

Parameters

params Named parameters:
- Mask A raster band, which is used as a mask to select sieved areas. Default is undef.
- Dest A raster band into which the result is written. If not given, an new in-memory raster band is created and returned.
- Threshold The smallest area size (in number of cells) which are not sieved away.
- Options Hash or list of options. {Connectedness => 4} can be specified to use 4-connectedness, otherwise 8-connectedness is used.
- Progress Progress function.
- ProgressData Additional parameter for the progress function.

Returns: The filtered raster band.

Code:

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public list Geo::GDAL::Band::Size ( )

Object method.

Returns: The size of the band as a list (width, height).

Code:

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public method Geo::GDAL::Band::Unit ( scalar type )

Object method.

Parameters

type	[optional] the unit (a string).

Note: $band->Unit(undef) sets the unit value to an empty string.

Returns: the unit (a string).

Since: version 1.9 of the bindings.

Code:

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public method Geo::GDAL::Band::WriteRaster ( hash params )

Object method.
Write data into the band.

Parameters

params Named parameters:
- XOff x offset (cell coordinates) (default is 0)
- YOff y offset (cell coordinates) (default is 0)
- XSize width of the area to write (default is the width of the band)
- YSize height of the area to write (default is the height of the band)
- Buf a buffer (or a reference to a buffer) containing the data. Create the buffer with pack function of Perl. See Geo::GDAL::Band::PackCharacter.
- BufXSize (default is undef, i.e., the same as XSize)
- BufYSize (default is undef, i.e., the same as YSize)
- BufType data type of the buffer (default is the data type of the band)
- BufPixelSpace (default is 0)
- BufLineSpace (default is 0)

Entry in GDAL docs (method RasterIO)

Code:

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public method Geo::GDAL::Band::WriteTile	(	scalar	data,
		scalar	xoff = `0`,
		scalar	yoff = `0`
	)

Object method.
Write band data from a Perl array.

Note: Accessing band data in this way is slow. Consider using PDL and Geo::GDAL::Band::Piddle.

Parameters

data	A two-dimensional Perl array, organizes as data->[y][x], y = 0..height-1, x = 0..width-1.
xoff
yoff

Code:

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The documentation for this class was generated from the following file:

all.dox

Public Member Functions

Public Attributes

Detailed Description

Member Function Documentation